Why is winter in the southern hemisphere and spring in the northern hemisphere?

The starting point of direct sunlight in spring is in the southern hemisphere.

The solar terms are divided by the method of "fixing qi", and beginning of spring is when the sun reaches longitude 3 15. In the era of cadres and branches, taking beginning of spring as the beginning of a year, beginning of spring means the beginning of a new cycle, the beginning of everything, and the meaning of all self-renewal.

Before Qin and Han Dynasties, the focus of etiquette and custom was not on January 1st of the lunar calendar, but on beginning of spring Day. Major festivals, such as offering sacrifices to ancestors, receiving blessings and praying for the New Year, exorcising evil spirits and fighting disasters, welcoming the old and welcoming the new, welcoming the spring and celebrating agriculture, are held at the beginning of spring and a few days before and after. This series of festivals not only constitutes the framework of the New Year's Eve Festival in later generations, but also retains its folk function to this day.

Law of activity

At the beginning of July, the earth is farthest from the sun, and the days in the northern hemisphere are long and the nights are short, while the southern hemisphere is just the opposite. The perihelion is after 1 month, and the days are shorter and the nights are longer in the northern hemisphere.

65438+1The perihelion distance at the beginning of October is 1.4765438+ 1 100 million kilometers, the angular velocity is 6 1 minute, and the antenna speed is 30.3 kilometers per second.

At the beginning of July, the distance between the sun and the earth at the far sun point was 1.52 1 100 million kilometers, the angular velocity was 57 minutes/day, and the linear velocity was 29.3 kilometers/second.

Perihelion is fast, the sun is far away and the day is slow.

Every year on March 2 1 or so, the vernal equinox is long day and night.

Every year around June 22nd (Northern Hemisphere), the days are long and the nights are short.

Every year around September 23rd, the autumnal equinox is long day and night.

Every year around 65438+February 22nd? Winter solstice has short days and long nights (northern hemisphere).

The equator is as long as day and night all the year round.